Abstract: Methods and apparatuses for detecting full waste canister and/or fluid flow path blockage conditions are disclosed. Also disclosed are methods and apparatuses for controlling a pump. In some embodiments, flow of fluid can be restricted in a portion of the fluid flow path. A controller can be configured to compare a difference in pressure values upstream and downstream of a fluid flow restrictor to a pressure difference threshold, and determine based on the comparison whether to activate an alarm indicating the full waste canister condition or the fluid flow path blockage condition. The controller can be additionally or alternatively configured to determine a fluid flow using a flow meter, open a selectable valve in response to a comparison of the fluid flow with a fluid flow threshold, determine fluid flow after opening the valve, and determine based on the fluid flow after opening the valve whether to activate the alarm.

Abstract: Embodiments described herein relate to a flow meter assembly. The inline flow meter assembly includes a housing, an elongated flow member, and a piston. The housing includes a fluid passage. The elongated flow member has a shaft portion and an opposite fluid flow portion. The fluid flow portion has an outer peripheral surface. The shaft portion is coupled to the housing. The piston has a plate. The plate has a plate orifice. The piston and the plate move axially between a no flow position where the outer peripheral surface of the fluid flow portion is engaged with the plate orifice to prevent a fluid flow and a full flow position where the outer peripheral surface of the fluid flow portion is disengaged with the plate orifice such that the fluid flow enters the plate orifice and passes through the fluid passage in the axial direction of movement of the piston.

Abstract: A valve trim assembly configured to be disposed in a fluid flow control valve, including, a valve seat adapted to be disposed in a fluid passageway of the fluid flow control valve. The valve seat includes an annular flange and a seating surface spaced from the annular flange. The valve trim assembly additionally includes a fluid control member movable relative to the valve seat to control fluid flow through the fluid passageway, wherein the fluid control member is movable from a closed position, in which the fluid control member sealingly engages the seating surface of the valve seat, and an open position, in which the fluid control member is spaced from the seating surface, by moving the fluid control member away from the annular flange of the valve seat.

Abstract: A method includes obtaining pressure measurements associated with fluid that passes through a flow restrictor, where the pressure measurements identify pressures upstream and downstream from the flow restrictor. The method also includes generating estimated flow measurements based on the pressure measurements. The method further includes comparing the estimated flow measurements and actual flow measurements generated by a flow meter that is fluidly coupled to the flow restrictor. In addition, the method includes determining whether a problem exists based on the comparison. The flow restrictor could provide a fixed restriction or a variable restriction for the fluid. An overall loss coefficient associated with the flow restrictor could be used to generate an estimated flow measurement.

Abstract: A method includes obtaining actual flow measurements generated by a flow meter, where the actual flow measurements identify a flow of material in a passageway. The method also includes generating estimated flow measurements based on process variable measurements other than the actual flow measurements. The method further includes comparing the estimated flow measurements and the actual flow measurements and determining whether a problem exists based on the comparison. The estimated flow measurements could be generated using one or more models mathematically representing how the flow of material in the passageway relates to non-flow process variables associated with the process variable measurements. The process variable measurements could be obtained from one or more sensors associated with a flow restrictor in the passageway, one or more sensors positioned within the passageway, and/or one or more sensors positioned outside the passageway.

Abstract: An electronic device for detecting an air flow includes at least one sensor having a pair of platelets, each platelet having an RTD and having one end fixed, the other end being free and overlapping the free end of the other platelet. A platelet is flexible so as to form a switch for an electrical circuit. An air flow with a speed higher than a predetermined speed makes the sensor go from a first state, corresponding to a closed switch, in which the free ends of the platelets are in contact, to a second state, corresponding to an open switch, in which said contact is broken. A detection module allows, for each sensor, a resistance of the electrical circuit to be measured, the resistance corresponding to the RTDs being connected in parallel when the switch is closed or to one of the RTDs when the switch is open.

Abstract: The invention relates to an orifice system, especially for flow measurements in pipes, comprising a hinged member being adapted to be moved between two positions, the first position essentially covering the pipe cross section, and a second position into a recess outside the pipe cross section, wherein the hinged member has an opening thus in the first position allowing the fluid flow only through the opening. The invention also relates to a method for using the orifice system for calibrating pressure sensors mounted upstream and downstream of the orifice.

Abstract: There is provided a fluid transducer. The transducer housing includes a nose section, a middle section, and a rear section, with the nose section defining a through bore. A sensor is disposed in the nose section and is in fluid communication with the through bore. An electronic module is disposed in the middle section and is in electrical communication with the sensor. A cap is coupled to the real section of the transducer housing, with the cap configured to seal the rear section of the transducer housing. A conductor-insulator assembly is coupled to an outer surface of the transducer housing and the conductor of the conductor-insulator assembly is coupled to the electronic module. In one embodiment the conductor-insulator assembly is annular in shape, with an inside diameter corresponding to the outer surface of the transducer housing.

Abstract: There is provided a flow transducer and method to sense flow of a fluid. The flow transducer includes a housing defining an internal passage way therethrough. A flow rate apparatus is disclosed in the internal passageway. The proximity sensor is coupled to the housing, with the proximity sensor aligned radially with the flow rate apparatus. A pair of annular conductor-insulator assemblies are coupled to an outer surface of the housing, with each conductor in electrical communication with the proximity sensor. A cap is coupled to the housing and is configured to axially secure the conductor-insulator assemblies to the housing, with the cap defining an orifice axially aligned with the internal passageway. The proximity sensor is configured to produce an electrical signal as the flow rate apparatus rotates past the proximity sensor, the electrical signal corresponding to the flow of the fluid through the flow transducer.

Abstract: Fluid flow apparatus, such as a fluid flow meter, a fluid mixing device or a fluid dispersing device, includes a fluid displacement member (40) mounted in a conduit (20) and having a sloped exterior wall (48) forming a periphery on the member for deflecting the fluid to flow through a region of progressively decreasing area defined between the periphery of the member and the interior surface of the conduit. The displacement member is a hollow frustum (42) terminating at the plane of its outer peripheral edge (46) and accommodating flow measurements at or adjacent the axis of the conduit at or adjacent the plane of the peripheral edge of the displacement member.

Abstract: A flow metering device and method for monitoring flow of a liquid, has a body with an inlet port and an outlet port. A flow chamber is formed therein between a pair of laterally placed windows in the flow chamber. A light emitting source placed in one of the windows and a light receiver placed in a second of the windows. The flow chamber has a flow restricting and light stopping element held therein and movable between a rest position and an operating position.

Abstract: A flow meter having a scale with temperature set points corresponding to a flow rate that a known fluid flowing therethrough at the set point temperature must reach to ensure turbulent flow of the fluid through a cooling system of a specified diameter. The flow meter preferably includes a plurality of scales, each having temperature set points corresponding to a different sized passageway in the mold cooling system. The scales are printed on a sleeve, rotatably mounted on a cylindrical body of the flow meter. The scales are selectively rotated into view by an operator to permit the operator to use the appropriate scale corresponding to the diameter of the passageways of the cooling system with which the flow meter is to be used.

Abstract: Fluid flow apparatus, such as a fluid flow meter, a fluid mixing device or a fluid dispersing device, includes a fluid displacement member removeably mounted in a conduit and a pipe or tube extending through the wall of the conduit and having a portion extending through the displacement member to its downstream face for sensing flow conditions at the axis of the conduit downstream of the displacement member. The displacement member is removeably and replaceably mounted on the pipe or tube so that one displacement member can be replaced by one or more displacement members and thereby accommodate a very broad range of flows of various fluids, fluid suspensions and slurries.

Abstract: A variable area flow meter has a magnet carried by a piston which is moved to a position representing fluid flow. An array of magnetoresistive bridge sensors adjacent the path of magnet movement senses the magnet position. The bridges are unbalanced by the magnet field. The analog unbalance signals are read and processed in digital form to develop a flow signal. The flow meter circuits are powered from a 4–20 MA current loop or a remote power supply. Each bridge sensor is powered only when the bridge unbalance signal is being read, to minimize the power requirement.

Abstract: Disclosed is a bi-directional differential pressure flow sensor that is configured to establish a direction and flow rate of a fluid flow. The flow sensor includes a flow restriction member, a differential pressure sensor, and processing electronics. The flow restriction member is configured to produce a pressure drop when placed inline with the fluid flow. The differential pressure sensor is embedded or integral with the flow restriction member and produces a differential pressure signal that is indicative of the pressure drop. The processing electronics produces a flow rate signal that is indicative of the direction and flow rate of the fluid flow as a function of the differential pressure signal.

Abstract: An in-line gas flow rate sensor includes a movable flow orifice and a fixed flow restrictor adjacent the flow orifice for changing the gas flow through the flow orifice. The flow orifice and the flow restrictor are formed so that each uniform increment of flow orifice movement provides a constant percent of flow change through the flow orifice. A magnet fixed to the movable flow orifice provides changing magnetic flux corresponding to each uniform increment of flow restrictor movement. A magnetic flux sensor responds to the changing magnetic flux and provides an output corresponding to a constant percent of flow rate changes.

Abstract: Apparatus for determining fluid flow through a pressure regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values.

Abstract: In a proportioner for proportioning a fluid flow (&phgr;) from an input side of a first proportioning element (10) to an output side of a second proportioning element (10), the first and second proportioning elements comprise a membrane (12) provided with at least one opening (16) acting as a flow resistor for a medium to be proportioned, and a pressure sensor (14) integrated in the membrane (12) and used for detecting a pressure difference between the input side and the output side of the proportioning element (10). The proportioner comprises a pressure transducer for input-side application of a pressure to the medium to be proportioned. The first and the second proportioning element (10) are arranged in succession so as to permit, on the basis of the pressure drop across the membranes (12) of the two proportioning elements (10), the detection of clogging or blocking of the respective flow resistor provided in these membranes (12).

Abstract: A respiratory flow sensor, which is suitable for use near a patient, covers a broad gas volume flow measuring range with a low breathing flow resistance and good, reproducible measured signal quality at the same time. The respiratory flow sensor has a first air resistance body (3) with a blunt end and with an opposite pointed end. The air resistance body (3) is arranged between the measuring transducer (5), of which there is at least one, and the patient-side end (P) of the respiratory flow sensor. The pointed end of the first air resistance body (3) points toward the measuring transducer (5). A second air resistance body (4) with a pointed end is arranged between the measuring transducer (5), of which there is at least one, and the end of the respiratory flow sensor that is away from the patient. The pointed end of the second air resistance body (4) also points toward the measuring transducer (5).

Abstract: A differential pressure monitoring device utilizing two crystalline frequency sensors exposed to different pressures for generating two signals which are combined by a frequency mixer. Two offset based frequency crystal sensors are each exposed to different pressures and the resulting frequencies are mixed to measure the pressure differential between the two crystals. When the crystals are exposed to a common pressure, the crystals have an offset based frequency response that is consistent with pressure. When the two crystals are exposed to pressures, the offset frequencies are mixed together to create a differential frequency that is precisely related to the differential in the pressures placed on the two different crystal sensors.

Abstract: A proportioning element (10) for proportioning a fluid flow from an input side to an output side of the proportioning element (10) comprises a membrane (12) provided with at least one opening (16) acting as a flow resistor for a medium to be proportioned. The membrane (12) has additionally integrated therein a pressure sensor (14) used for detecting a pressure difference between the input side and the output side of the proportioning element (10). The proportioning element is implemented as a semiconductor chip, the membrane (12) being a semiconductor membrane and areas of the semiconductor chip which are exposed to the medium to be proportioned being provided with a passivation layer.

Abstract: A flow proportioning assembly for dividing a portion of a fluid flow such as gas for presentation to a sensor includes a holder member having a central opening and forming an exterior peripheral passageway when inserted within a conduit of a flow meter housing. A resistor member can be adjustably mounted in the central opening downstream of a holder member aperture to encourage a laminar flow pattern and a large entrance port and a large exit port can communicate with a passageway that is operatively connected with a sensor. The exit port is downstream of the resistor member. Flexible fastener members can engage the resistor member and the holder member for ease of mounting. The resistor member can also comprise a helical arrangement of small fluid passageways to encourage laminar flow.

Abstract: A water flow-sensing device includes an assembly with a stationary metering rod with a cylindrical portion and a conical portion and a relatively moveable element in the shape of a hollow cylindrical toroid. The relatively moveable element is biased by a spring to a rest position wherein the cylindrical portion of the stationary metering rod blocks flow through the relatively moveable element. During fluid flow, fluid pressure moves the relatively moveable element so that the conical portion of the stationary metering rod is within the hollow portion of the relatively moveable element thereby creating a flow area and allowing flow therethrough. A toroidal ferrite is biased against the relatively moveable element and moves in unison therewith. The position of the toroidal ferrite is electromagnetically determined thereby allowing for a calculation of the fluid flow therethrough. Low flowrates indicative of a trickle leak and large flowrates indicative of a large leak can be detected.